One of the important characteristic features of the oral cavity which has a great impact on the function of dental materials is the thermal change resulting from the consuming foods and drinks of different temperatures. Because the tooth and restoration materials have different thermal expansion coefficients, cold and hot drinks or foods exert different degrees of contraction and expansion in the tooth and dental filling materials. Eventually, this results in tiny gaps between them. By more accurately simulating oral conditions while studying dental materials and tooth structure, greater reliability in the results and greater certainty in applying these results to clinical conditions will be possible.
To simulate thermal shocks, studies typically use a thermal cycling unit. The common method of thermal cycling provides two liquid environments of 5° C. and 55° C. into which samples are placed in rapid succession. Despite its popularity in dental research, this method fails to accurately simulate the natural oral environment under in vitro conditions.
After a sip of hot tea or cold drink, the teeth and dental materials come into contact with the passing or showering liquid and then the saliva and normal oral temperatures surrounds them again. The balance temperature allows the stress exerted as a result of drinking liquids of different temperatures to be released without being accumulated in the material. This prevents the material from getting fatigued and broken very soon. However, this may not happen as a result of placing the samples in two different thermal baths of 5° C. and 55° C. in rapid and sudden succession since there is no balance temperature.
In conducting laboratory research, the materials, techniques and dental structure should be tested by the same shocks they receive in the oral cavity. The shocks can be exerted because of the temperature, chewing pressure, special eating or drinking habits, chemical elements such as acidic, basic, alcoholic, non-alcoholic and carbonated drinks as well as colored substances such as tea, coffee and juices. Research will allow for development of dental materials and techniques should be produced and developed so that they can resist such shocks.